Apparatus for automatically centering and aligning moving objects



@fg/@WW2 Lele/25222222 APPARATUS FOREL-I'OMATICALLY CENTERING FIE FIEI- AND ALIGNING MOVING OBJECTS Filed June 4 i @@@QQQQQQQQ Dec. 23, 1952 Patented Dec. 23, 1952 UNITED APPARATUS FOR AUTOMATICALLY CEN- TERING ANDALIGNING`MOVING OBJECTS Jersey Application June,4,`1951, Serial No.2'29;722

L4 Claims. -l This invention relates to apparatus'for automatically `centering and aligningymoving -ob jects, especially strip Aand strip-'like-'materiala In the processing of metal strip, -the stripis conveyed over rolls in the uncoiled condition. When the strip `is conveyed 4over la roll'to the processing equipment itl is likely `that the strip will be fed at a slight `angle to Athe-roll. Because of this, 'the .strip will work Vits Way across `the face of the roll. In additionythe camber and/ orflateral curvature which is'present in thenished strip due to rolling "diiculties 'causes the strip edges and longitudinal Vcenter ,line 'to yapproach the roll `at an angle, this 'also causing the strip to move 'across the face of 'the roll. In order to keep the strip inthe "desired path of travel, various expediente` have been resorted to. One of the Vmost common is vthe use of 'stationary or rotatable side Vguides against whichthe vedgesof the strip bear. rIn some instances'side'guideslfiave been used in conjunction With looper Vpits to force the strip back on the desired center line. The use of abnormally high strpiptension hasalso been tried in "an attempt 'to 'keep 4the strip aligned. periodically .slip or sluethe Astrip 'back into its approximate proper` position .onthe conveying roll. All ofthe abovemethods of -centering strip tend to abrade and mutilate the strip 'edges and in some instances ,cause the edges ofthe strip to be stretched beyond the elastic limit-ofthe metal. Diagonal or 'lateral surface scratches 'are 'also formed -on finely .finished flat products o'f "all kinds, these scratches being detrimental to subsequent operations and together With edge damage result in the scrapping of a large percentage of 'the `material being processed. The problems discussed above also exist in belt 4conveyors and drive belts :used in conjunction Withjbelt pulleys. If the belt is made of rubber or other relatively soft material, it is more easily damaged. Iny addition to the methods of aligning strip mentioned above, crow-n rolls have 'been used to center materials having a low modulus of elasticity ,such as textiles, rubber and composition belts.

Various types of apparatus suitable for centering and aligning strip are shown in my copending applications entitled Apparatus for Positioning Strip, Serial No. 97,218, led June 4, 1949, now Patent No. 2,593,157, Method and Apparatus for Positioning Strip, Serial No. 138,- 389, led January 13, 1950, now Patent No. 2,592,581, and Method and Apparatus for Positioning Strip, Serial No. 145,648, led February 23, 1950, now Patent No. 2,593,158.

Another method of ',operation'is Vto lIt isanobjectof the present 'invention toiprovide apparatus for automatically l centering -moving objects without damage thereto.

This and -other objects vwill `be more apparent after referring to the following `description and attached drawings, -in which:

Figure lv is a sectional view of one embodiment of my invention with no -load 4applied thereto;

Figure 2 is-a view similar to Figure 4lfbut showing a load applied thereto;

Figure 3 "is a view, similar -to lifigure 1, vshowing a ysecond Aembodimentwof my invention;

-Figure 4-is aviewfsimilar to "Figure y1,shovving a third embodiment of 4my invention;

-Eigure 5 Yis 4a View, similar to Figure v4, but showing a load applied-theretoyand Figure 6 isa schematicview taken on the -line VI-VI of Figure 5.

Referring more particularly -to Figures' `l and j2 of the drawings, the referencemumeral 2 indicates a rotatable shaft mounted in bearingsll. The shaft 2 may be either idle or driven, in which latter case an extension E is provided at one end for connection to a -driving mechanism (not-shown). A pair of opposed `spirally wound springst and lilV surround Ithe shaft 2 Awith their outer ends rigidlysecured to the shaft at points l2 and `I4 adjacent thev bearings 4. VThe springs 8 and Hl are preferably frusto-conical in shape with vthe large diameter ends adjacent eachother sothattheadjacent ends `of the `springs Vcan move inwardly toWar-d the axis 'of the shaft '2. However, thefoutside diameter Vof the springs may be made larger at their adjacent Vends than at their outer ends by grinding :off material 'from the outer surface of the spring'as shown inFigure'S. It will .be understood that `the conical effect is greatly exaggerated for the purpose of illustration and that the strip S will normally be flat instead ,of convex .as shown in Figure r2.

When pressure is applied to thesurface ofthe springs 8 and Hl by means of afstrip S., 'the rotating rims of the 'springsmove inwardly toward their Aaxes 'tothe point of contact and outwardly at a point diametrically opposite. The rotation of the springsunderfpressure appliedbythe strip S willgcontinue in Ya tilted Amanner as shown lin Figurey 2 ,as ,long as ,pressure is applied by the strip. If the strip S is in centered position and its bearing pressure on the springs is uniform over its full width no lateral movement of the strip Will occur. However, when the strip is offcenter or the strip contact is non-uniform from side to side the spring having the greatest total amount of tension and pressure applied thereto will produce a greater lateral pressure on the strip than the other spring so that the strip S will be forced to centered position. In certain applications there will be only line contact between the roll and the object passing thereover and in other instances the strip S may be wrapped around an arc of the spring.

In the embodiment of my invention shown in Figure 3 a spring 9 of uniform inside diameter is mounted on stub shafts 2a and part of the outside surfaces of the coils are ground off to give the desired frusto-conical shape. The operation in this case is the same as that described above. The spring 9 is in effect a pair of springs connected at their adjacent ends to cause them to rotate in unison, this being necessary for proper functioning of the apparatus. The centering device of Figure 3 is especially suitable for centering a troughed conveyor belt.

Figures 4 to 6 show an embodiment of my invention which incorporates features of each'of the first two embodiments. In this embodiment the two coil springs 8 and I8 are connected at their centers as shown so that in effect there is a single coil spring I6. Figure 4 shows this roll or spring without any load being applied thereto. Figure 5 shows a load being applied to the spring I6 by means of an endless belt B. The endless beltB also passes around a conventional pulley I8 spaced from the spring I6 as shown in Figure 6. It will be seen that the convolutions of the spring I6 are forced against the shaft 2 by means of the belt B which surrounds the spring over an arc of approximately 180. The operation of this embodiment is the same as that set forth above for the rst embodiment.

, While several embodiments of my invention have been shown and described it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. In combination with an endless belt and a pulley around which the belt passes, a rotatable belt supporting member for automatically centering the belt comprising a pair of spaced bearings, a shaft section rotatably mounted in each of said bearings, a pair of axially opposed rotatable spirally wound springs forming a supporting surface for said belt, said springs being coaxial, the outside diameter of each of said springs progressively increasing in size from their outer ends to their adjacent ends, the arrangement and spacing of the coils being such that each spring may flex in a direction transverse to its longitudinal axis and about its end of smaller diameter as a pivot, means connecting the outer end of one of said springs to the first of said shaft sections, means connecting the outer end of the other of said springs to the second of said shaft sections, and means for positively causing the springs to rotate in unison.

2. In combination with an endless belt and a pulley around which the belt passes, a rotatable belt supporting member for automatically centering the belt comprising a pair of spaced bearings, a shaft section rotatably mounted in each of said bearings, a pair of axially opposed rotatable spirally Wound springs forming a sup- 4 porting surface for said belt, said springs being coaxial, the outside diameter of each of said springs progressively increasing in size from their outer ends to their adjacent ends, the arrangement and spacing of the coils being such that each spring may flex in a direction transverse to its longitudinal axis and about its end of smaller diameter as a pivot, means connecting the outer end of one of said springs to the first of said shaft sections, means connecting the outer end of the other of said springs to the second of said shaft sections, means for positively causing the springs to rotate in unison, and means for connecting the adjacent ends of said springs.

3. In combination with an endless belt and a pulley around which the belt passes, a rotatable belt supporting member for automatically centering the belt comprising a pair of spaced bearings, a pair of axially opposed rotatable spirally Wound springs forming a supporting surface for said belt. said springs being coaxial, the outside diameter of each of said springs progressively increasing in size from their outer ends to their adjacent ends, the arrangement and spacing of the coils being such that each spring may flex in a direction transverse to its longitudinal axis and about its end of smaller diameter as a pivot, a rotatable shaft extending axially through said springs and supported in said bearings, and means for attaching the outer ends of said springs to said shaft, the internal diameter of the central coils of said springs being greater than the diameter of said shaft.

4. In combination with an endless belt and a pulley around which the belt passes, a rotatable belt supporting member for automatically centering the belt comprising a pair of spaced bearings, a pair of axially opposed rotatable spirally wound springs forming a supporting surface for said belt, said springs being coaxial, the outside diameter of each of said springs progressively increasing in size from their outer ends to their adjacent ends, the arrangement and spacing of the coils being such that each spring may flex in a direction transverse to its longitudinal axis and about its end of smaller diameter as a pivot, a rotatable shaft extending axially through said springs and supported in said bearings, means for attaching the outer ends of said springs to said shaft, the internal diameter of the central coils of said springs being greater than the diameter of said shaft, and means for connecting the adjacent ends of said springs.

EDWIN T. LORIG.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 331,328 Randall 1 Dec. 1, 1885 563,651 Brooks July 7, 1896 774,699 Sagerdahl Nov. 3, 1904 2,391,178 McKnight Dec. 18, 1945 FOREIGN PATENTS Number Country Date 19,403 Great Britain Sept. 9, 1893 

